I sympathize with this viewpoint, but I need to play devil's advocate a little, to highlight the problems with predictive diagnoses: Most Americans with this g

I sympathize with this viewpoint, but I need to play devil's advocate a little, to highlight the problems with predictive diagnoses: Most Americans with this genotype go on to develop late-onset dementia. Let's say "most" is 90%. Let's also say the accuracy of this test is (and I don't know if this is realistic or not) 98%. Does the 11.8% chance of no dementia on a positive result give me enough to follow through with a plan? For me, no, though I appreciate attitudes would vary.